← Courses

Python for AI — Beginner Foundations

Data Science

Functions · Lesson 40 of 76

Defining functions

A function is a reusable block of code with a name. Define it with def, then call it:

Python

Functions keep your program tidy: write the logic once, use it anywhere.

Your turn: write area(width, height) that returns width * height, then print area(4, 5).

Check your understanding

Exercise — check your understanding

Write a function area(width, height) that returns width times height.

You’re reading for free. Sign in to keep your progress and earn a certificate when you finish.Sign in to keep my progress →